The invention relates to communicating ancillary information associated with a plurality of audio/video programs, such as television content associated with a plurality of channels.
Ancillary information, such as program sub-titles, emergency messages, closed caption messages, and program guide information, may be transmitted with regular television content. More recently, other types of ancillary information that may be sent with television content include enhancement data such as web pages, multimedia information, or other digital data files. Ancillary information may be sent in the vertical blanking interval (VBI) of an analog television broadcast signal. Alternatively, the ancillary information may be sent with digital television content over a digital transport medium.
Various standards exist that provide for transmission of ancillary information with television content. One standard is the Advanced Television Enhancement Forum (ATVEF) Specification, Draft Version 1.1r26, dated Feb. 2, 1999. The ATVEF Specification is designed to provide for transmission of enhancement data along with television content in both analog and digital systems, such as cable systems, satellite systems, terrestrial systems, and so forth. The combination of the enhancement data and the television content may be referred to as enhanced television content. Enhanced television content provides more information and options to viewers. For example, a viewer may be presented with the option of viewing advertisements, educational information, and so forth, while watching regular television programming.
Transmission of enhanced television content, however, may increase bandwidth requirements of the transport medium between the transmission source and receiving sites. Thus, a need exists to provide for solutions that address bandwidth limitations of transport media as well as provide for greater flexibility in the transmission of such ancillary information.